1
|
[K 2(Bi@Pd 12@Bi 20)] 4-: An Endohedral Inorganic Fullerene with Spherical Aromaticity. J Am Chem Soc 2024; 146:14166-14173. [PMID: 38717077 DOI: 10.1021/jacs.4c03024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/23/2024]
Abstract
Inorganic fullerene clusters have attracted widespread attention due to their highly symmetrical geometric structures and intrinsic electronic properties. However, cage-like clusters composed of heavy metal elements with high symmetry are rarely reported, and their synthesis is also highly challenging. In this study, we present the synthesis of a [K2(Bi@Pd12@Bi20)]4- cluster that incorporates a {Bi20} cage with pseudo-Ih symmetry, making it the largest main group metal cluster compound composed of the bismuth element to date. Magnetic characterization and theoretical calculations suggest that the spin state of the overall cluster is a quartet. Quantum chemical calculations reveal that the [Bi20]3- cluster has a similar electronic configuration to C606- and the [Bi@Pd12@Bi20]6- cluster exhibits a unique open-shell aromatic character.
Collapse
|
2
|
[Ag(Sn 9-Sn 9)] 5- and [(η 4-Sn 9)Ag(η 1-Sn 9)] 7-, as aggregates of spherical aromatic building blocks. Persistence of aromaticity upon cluster gathering. Phys Chem Chem Phys 2024; 26:8419-8425. [PMID: 38407459 DOI: 10.1039/d3cp05394f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/27/2024]
Abstract
Formation of cluster-based materials requires a fundamental understanding of the resulting cluster aggregation processes. The Sn94- Zintl-ion structure can be viewed as a building block featuring a spherical aromatic species, leading to a cluster gathering upon oxidative coupling and/or mediated by transition metals. Here, we evaluate the spherical aromatic properties of [Sn9-Sn9]6-, [Ag(Sn9-Sn9)]5- and [(η4-Sn9)Ag(η1-Sn9)]7-, as aggregates of two Sn9 building units held together via oxidative coupling and mediated by a Ag(I) transition metal center. Our results from magnetic criteria of aromaticity show that the inherent spherical aromatic characteristics of the parent Sn94- cluster are persistent in the overall aggregate where the enabled shielding cones ascribed to each Sn9 unit are able to interplay between them, leading to an overlap of the shielding regions. Hence, the two approaches for bringing cluster units together are able to retain the inherent spherical aromatic features for each Sn9 unit, leading to a cluster-based dimer where the parent properties remain. Thus, further cluster-based materials can be envisaged from aggregation upon oxidative coupling and/or mediated by transition metals, where the constituent building blocks retain their initial features, useful to guide the formation of more complex cluster-based aggregates.
Collapse
|
3
|
Ligand-free supermolecules: [Pd 2@Ge 18] 4- and [Pd 2@Sn 18] 4- as multiple-bonded Zintl-ion clusters based on Pd@Ge 9 and Pd@Sn 9 assembled units. NANOSCALE 2024. [PMID: 38436401 DOI: 10.1039/d4nr00220b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/05/2024]
Abstract
Understanding intercluster bonding interactions is important in the rational synthesis of building blocks for molecular materials. Such characteristics have been developed for coinage metal clusters resembling single-, double-, and triple-bonded species, coined as supermolecules. Herein, we extend such an approach for understanding main-group clusters, thus evaluating [Pd2@E18]4- clusters (E = Ge, Sn) involving the fusion of parent spherical aromatic [Pd@E12]2- building units. Our results indicate intercluster bonding provided by contribution from 2P and 1G shells centered at each building motif, leading to an overall bond order of 2.70 and 2.31 for [Pd2@Ge18]4- and [Pd2@Sn18]4-, respectively. In addition, 119Sn-NMR patterns were evaluated to complement the experimental characterization of a single peak owing to the insolution fluxional behavior of [Pd2@Sn18]4- as three peaks owing to the three sets of unique Sn atoms within the structure. Magnetic response properties revealed that spherical aromatic characteristics from parent [Pd@E12]2- building units are retained in the overall [Pd2@E18]4- oblate cluster as two spherical aromatic units. Hence, the notion of superatomic molecules is extended to Zintl-ion clusters, favoring further rationalization for the fabrication of cluster-assembled solids.
Collapse
|
4
|
Classical Gold Carbonyl Complexes in Tetrahedral and Trigonal-Planar Settings. Chemistry 2024; 30:e202303339. [PMID: 37929919 DOI: 10.1002/chem.202303339] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Revised: 11/03/2023] [Accepted: 11/06/2023] [Indexed: 11/07/2023]
Abstract
A unique four-coordinate, classical gold(I)-carbonyl complex with substantial backdonation from gold has been isolated by using a B-methylated and fluorinated tris(pyridyl)borate chelator. Its lighter silver(I) and copper(I) analogs enabled a study of trends in the coinage-metal family. The B-arylated ligand version also afforded a gold-carbon monoxide complex that displays a notably low C-O stretch value, but with trigonal planar geometry at the gold. A computational analysis shows that the AuI -CO bonds of these tris(pyridyl)borate ligand-supported molecules consist of electrostatic attraction, OC→Au σ-donation, and very significant Au→CO π-back-bonding components. The latter is responsible for the observed C-O stretching frequencies, which are lower than in free CO.
Collapse
|
5
|
Second-order superatoms: Au 52-PAP featuring a three-dimensional cluster-of-clusters core. Dalton Trans 2023; 52:17696-17700. [PMID: 37990872 DOI: 10.1039/d3dt02693k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2023]
Abstract
The recent characterization of Au52-PAP cluster can be viewed as a three-dimensional arrangement featuring four Au13 motifs. As a result, a new set of superatomic orbitals are built up from the superatomic shell of each constituent unit, denoted by 1S'21P'62S'21D'102P'61F'6 and, thus, referred to as a second-order superatomic shell structure. This favors the rationalization of larger species toward the formation of cluster-assembled materials of different sizes.
Collapse
|
6
|
An all-metal fullerene: [K@Au 12Sb 20] 5. Science 2023; 382:840-843. [PMID: 37972185 DOI: 10.1126/science.adj6491] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2023] [Accepted: 10/04/2023] [Indexed: 11/19/2023]
Abstract
The C60 fullerene molecule has attracted tremendous interest for its distinctive nearly spherical structure. By contrast, all-metal counterparts have been elusive: Fullerene-like clusters composed of noncarbon elements typically suffer from instability, resulting in more compact geometries that require multiple embedded atoms or external ligands for stabilization. In this work, we present the synthesis of an all-metal fullerene cluster, [K@Au12Sb20]5-, using a wet-chemistry method. The cluster's structure was determined by single crystal x-ray diffraction, which revealed a fullerene framework consisting of 20 antimony atoms. Theoretical calculations further indicate that this distinct cluster exhibits aromatic behavior.
Collapse
|
7
|
Thallium(I) Complexes of Tris(pyridyl)borates and a Comparison to Their Pyrazolyl Analogues. Inorg Chem 2023; 62:18563-18572. [PMID: 37906103 DOI: 10.1021/acs.inorgchem.3c02805] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2023]
Abstract
Thallium(I) complexes of B-methylated and B-phenylated tris(pyridyl)borates featuring trifluoromethyl groups at the pyridyl ring 6-positions have been synthesized by metathesis using the corresponding potassium salts [MeB(6-(CF3)Py)3]K and [PhB(6-(CF3)Py)3]K with thallium(I) acetate. The closely related tris(pyrazolyl)borate analogue [PhB(3-(CF3)Pz)3]Tl has also been prepared, and comparisons of structural and spectroscopic features between the two scorpionate families are presented. [MeB(6-(CF3)Py)3]Tl displays κ3-coordination of the tris(pyridyl)borate similar to that of tris(pyrazolyl)borate in [MeB(3-(CF3)Pz)3]Tl, while [PhB(6-(CF3)Py)3]Tl and [PhB(3-(CF3)Pz)3]Tl feature κ2-N,N ligand coordination modes with the B-phenyl groups flanking the thallium sites. 19F NMR spectroscopy of [MeB(6-(CF3)Py)3]Tl reveals the presence of a remarkably large 1208 Hz four-bond thallium-fluorine coupling constant in chloroform at room temperature, which is considerably larger than 878 Hz observed for the pyrazolyl borate analogue [MeB(3-(CF3)Pz)3]Tl. Although [PhB(6-(CF3)Py)3]Tl is structurally nonrigid at room temperature in chloroform, at lower temperatures, the ligand arm exchange slows down, revealing 4JTl-F = 1110 Hz. Steric demands of these ligands have been quantified using the buried volume concept. In addition, ligand transfer chemistry from [MeB(6-(CF3)Py)3]Tl and [PhB(6-(CF3)Py)3]Tl to copper(I) under ethylene and computational analyses of the various coordination modes of tris(pyrazolyl)borates and tris(pyridyl)borates are reported.
Collapse
|
8
|
On the structure and electronic properties of Pt n clusters: new most stable structures for n = 16-17. Phys Chem Chem Phys 2023; 25:28835-28840. [PMID: 37853760 DOI: 10.1039/d3cp04455f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2023]
Abstract
The lowest energy structures and electronic properties of Ptn clusters up to n = 17 are investigated by using a genetic algorithm in combination with density functional theory calculations. There are several putative global minimum structures for platinum clusters which have been reported by using different approaches, but a comprehensive study for n = 15-17 has not been carried out so far. Herein, we perform a consensus using GGA (PBE), meta-GGA (TPSS) and hybrid (B3PW91, PBE0, PBEh-3c, M06-L) functionals in conjunction with the Def2-TZVP basis set. New most stable structures are found for Pt16 and Pt17, which are slightly lower in energy than the previously reported global minima. Molecular dynamics simulations show that the clusters are rigid at room temperature. We analyze the structural, electronic, energy and vibrational data of the investigated clusters in detail.
Collapse
|
9
|
Antifungal activity of Co(II) and Cu(II) complexes containing 1,3-bis(benzotriazol-1-yl)-propan-2-ol on the growth and virulence traits of fluconazole-resistant Candida species: synthesis, DFT calculations, and biological activity. BMC Chem 2023; 17:135. [PMID: 37817173 PMCID: PMC10563319 DOI: 10.1186/s13065-023-01037-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Accepted: 09/13/2023] [Indexed: 10/12/2023] Open
Abstract
Relevant virulence traits in Candida spp. are associated with dimorphic change and biofilm formation, which became an important target to reduce antifungal resistance. In this work, Co(II) complexes containing a benzotriazole derivative ligand showed a promising capacity of reducing these virulence traits. These complexes exhibited higher antifungal activities than the free ligands against all the Candida albicans and non-albicans strains tested, where compounds 2 and 4 showed minimum inhibitory concentration values between 15.62 and 125 μg mL-1. Moreover, four complexes (2-5) of Co(II) and Cu(II) with benzotriazole ligand were synthesized. These compounds were obtained as air-stable solids and characterized by melting point, thermogravimetric analysis, infrared, Raman and ultraviolet/visible spectroscopy. The analysis of the characterization data allowed us to identify that all the complexes had 1:1 (M:L) stoichiometries. Additionally, Density Functional Theory calculations were carried out for 2 and 3 to propose a probable geometry of both compounds. The conformer Da of 2 was the most stable conformer according to the Energy Decomposition Analysis; while the conformers of 3 have a fluxional behavior in this analysis that did not allow us to determine the most probable conformer. These results provide an important platform for the design of new compounds with antifungal activities and the capacity to attack other target of relevance to reduce antimicrobial resistance.
Collapse
|
10
|
Cl@Si 20X 20 cages: evaluation of encapsulation nature, structural rigidity, and 29Si-NMR patterns using relativistic DFT calculations. Phys Chem Chem Phys 2023. [PMID: 37455622 DOI: 10.1039/d3cp02371k] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/18/2023]
Abstract
The experimental characterization of Cl@Si20 endohedral clusters, featuring different ligands such as [Cl@Si20H20]- (1) [Cl@Si20H12Cl8]- (2), and [Cl@Si20Cl20]- (3), provides insight into the variable encapsulation environment for chloride anions. The favorable formation of such species enables the evaluation of the encapsulation nature and the role of the inner anion in the rigidity of the overall cluster. Our results show a sizable interaction which increases as -66.7, -100.8, and -130.3 kcal mol-1 from 1 to 3, respectively, featuring electrostatic character. The orbital interaction involves 3p-Cl → Si20X20 and 3s-Cl → Si20X20 charge transfer channels and a slight contribution from London dispersion-type interactions. These results show that the inner bonding environment can be modified by the choice of exobonded ligands. Moreover, 29Si-NMR parameters are depicted in terms of the chemical shift anisotropy (CSA), leading to a strong variation of the three principal tensor components (δ11, δ22, δ33), unraveling the origin of the experimental 29Si-NMR chemical shift (δiso) differences along the given series. Thus, the Si20 cage is a useful template to further evaluate different environments for encapsulating atomic species.
Collapse
|
11
|
Charge delocalization and aromaticity of doubly reduced double-walled carbon nanohoops. Phys Chem Chem Phys 2023. [PMID: 37448229 DOI: 10.1039/d3cp01994b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/15/2023]
Abstract
Cycloparaphenylenes (CPPs) exhibit selective host capabilities, featuring the ability to incorporate smaller CPPs to form double-walled host-guest complexes. Moreover, CPPs can also be stabilized by global aromaticity under twofold oxidation or reduction, involving electronic conjugation along with the overall structural backbone. Herein we explore the structural modifications, bonding, electron delocalization and magnetic properties of doubly reduced double-walled CPP complexes with DFT methods, in the isolated and aggregate [n + 5]CPP⊃[n]CPP2- (n = 5-8) species. Our results show that the hosts undergo structural, bonding and delocalization deformations towards quinoidal configurations and exhibit global long-ranged shielding cones similar to global aromatic free dianionic CPPs, accounting for charge delocalization on the outer nanohoops, whereas the guests preserve local aromatic benzenoid configurations, resulting in global and local aromatic circuits within the host-guest aggregate. This observation suggests that in multi-layered related species electronic delocalization will be retained at the outer structural surface. The aromaticity of the hosts is manifested in the strong upfield shifts of the guests 1H-NMR signals. Hence, CPP complexes can be extended to doubly reduced species stabilized by global host aromaticity expanding our understanding of doubled-walled nanotubes at the nanoscale regime.
Collapse
|
12
|
Local and global aromaticity under rotation: analysis of two- and three-dimensional representative carbon nanostructures. Phys Chem Chem Phys 2023; 25:14285-14293. [PMID: 37183443 DOI: 10.1039/d3cp00569k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Nanoscaled 2D and 3D carbon structures with closed curved π-surfaces are of relevance in the development of desirable building units for materials science. Such species are able to sustain local and global aromatic circuits involving isolated regions or the overall structural backbone, respectively. Here we account for local and global aromaticity under rotation of representative two- and three-dimensional species involving para-connected and fused edge-sharing phenyl rings ([8]CPP, [10]CPP, CNB), and C60 fullerene at different charge states. Our results denote that nanoscaled 2D global aromatics mimic the behaviour of the most prototypical aromatic 6π-circuit, given by benzene, where the shielding cone properties vary along the rotation motion. In contrast, 3D spherical aromatics remain almost invariant under rotation, given the distinctive characteristics of such species, differing from 2D global aromatics. Dissection of orbital contributions reveals that π-orbitals are determinants for shifting from non-aromatic to spherical aromatic species. Under rotation, the variation of the anisotropic effect inherent to such nanoscaled structures is accounted for, which is relevant to rationalize variation in NMR signal shifts upon the formation of host-guest aggregates.
Collapse
|
13
|
Intermediate Silver Doping of Au 25(SR) 18: Variation of Electronic, Optical, and Chiroptical Properties along Au 25-xAg x(SH) 18- ( x = 0-12) Stoichiometry from DFT Calculations. Inorg Chem 2023; 62:7079-7086. [PMID: 37104868 DOI: 10.1021/acs.inorgchem.3c00485] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
Abstract
The silver analogue of the prominent Au25(SR)18 nanocluster reveals the possibility of finding "gold"-like behavior despite their different nature, in addition to the common features among molecular AgNP. Herein, we explore the effect of successive additions of silver atoms reaching an intermediate Ag/Au doping ratio where the parent gold cluster exhibits properties from both elements. Our results show a more favorable situation as the Ag/Au ratio increases along the Au25-xAgx(SH)18- (x = 0-12) clusters, with structural distortions mainly centered at the ligand-protected shell. The calculated optical spectrum shows that from the Au19Ag6 species, a plasmon-like peak appears along species with a doping ratio above 25%, where all the silver atoms are located within the M12 icosahedron. In addition, the chiral properties were explored, showing mild optical activity from the calculated circular dichroism spectra due to the distorted ligand-shell avoiding a centrosymmetric structure. Thus, an intermediate doping ratio ascribed to a specific structural layer can recover inherent properties to both elements in the binary Au25-xAgx(SH)18- series, suggesting the possibility of having clusters with dual properties at a certain degree of element exchange. This can be useful for further exploration theoretically and synthetically toward different and larger-nuclearity clusters.
Collapse
|
14
|
On the Cation-π capabilities of infinitene (∞). Evaluation of bonding and circular dichroism properties for Infinitene-Ag(I)n (n = 1–4) complexes from relativistic DFT calculations. Polyhedron 2023. [DOI: 10.1016/j.poly.2023.116323] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
|
15
|
Infinitene as two fused helicoidal trails of fused rings: evaluation of the magnetic behavior of [12]infinitene and anionic species displaying global aromaticity and antiaromaticity. Phys Chem Chem Phys 2023; 25:8190-8197. [PMID: 36880673 DOI: 10.1039/d2cp06039f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
The unique formation of an infinity-shaped carbon backbone made exclusively from fused benzene rings has recently been achieved. The structure of [12]infinitene can be viewed as two fused [6]helicene structures with a central crossover section, depicting a global aromatic behavior along with the overall structure, with deshielding regions along both helicoidal axes. In addition, the 13C-NMR characteristics are discussed. The formation of a cumulative region involving the shielding regions from the aromatic rings is depicted along with the overall aesthetically pleasant structural backbone, which is enhanced at the crossover section. For the evaluated dianionic counterpart, the structure shows a deshielding region above the fused-ring trail and a helicoidal shielding region, ascribed to a global antiaromatic counterpart. The aromaticity is recovered and enhanced at the tetranionic state. Thus, the neutral and tetranionic states are able to build up a long-ranged shielding region, given by the global aromatic behavior, with an enhanced shielding region at the center of the crossover section displaying π-π stacked rings.
Collapse
|
16
|
Aromaticity in P 8 allotropes and (CH) 8 analogues: significance of their 40 valence electrons? Phys Chem Chem Phys 2023; 25:9364-9372. [PMID: 36920848 DOI: 10.1039/d3cp00147d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/09/2023]
Abstract
The currently unknown phosphorus allotrope P8 is of interest since its 40 total valence electrons is a "magic number" corresponding to a filled 1S21P61D101S21F142P6 shell such as found in the relatively stable main group element clusters Al13- and Ge94-. However, P8 still remains as an elusive structure not realized experimentally. The lowest energy P8 structure by a margin of ∼9 kcal mol-1 is shown by density functional theory to be a cuneane analogue with no PP double bonds and two each of P5, P4, and P3 rings. Higher energy P8 structures are polycyclic systems having at most a single PP double bond. These P8 systems are not "carbon copies" of the corresponding (CH)8 hydrocarbons with exactly one hydrogen atom bonded to each carbon atom. Thus the lowest energy (CH)8 structure is cyclooctatetraene with four CC bonds followed by benzocyclobutene with three CC bonds. The cuneane (CH)8 structure is a relatively high energy isomer lying ∼36 kcal mol-1 above cyclooctatetraene. The cubane P8 and (CH)8 structures are even higher energy structures, lying ∼37 and ∼74 kcal mol-1 in energy above the corresponding global minima. Our results demonstrate differences in medium sized aggregates of elemental phosphorus and isolobal hydrocarbon species.
Collapse
|
17
|
Tuning Mechanically Interlocked Molecules to Recognize Anions and Cations: A Computational Study. Chemistry 2023:e202203905. [PMID: 36847391 DOI: 10.1002/chem.202203905] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 02/13/2023] [Accepted: 02/27/2023] [Indexed: 03/01/2023]
Abstract
Ions appear as active components in diverse materials. Here, the bonding energy between mechanically interlocked molecules (MIMs) or their acyclic/cyclic molecular derivatives and: i) Cl- and Br- anions; and/or ii) Na+ and K+ cations, have been investigated. The chemical environment provided by MIMs is less preferably to recognize ionic species compared to unconstrained interactions that are furnished by acyclic molecules.However, MIMs can be more adequate structures to ionic recognition than cyclic compounds if provide a chemical arrangement of the bond sites that relevantly support more favorable interactions with ions compared to Pauli repulsive ambient. The hydrogen replacement by electron donor (-NH2) or acceptor (-NO2) groups in MIMs favors the anion/cation recognition due to decreased Pauli repulsion energy and/or more attractive non-covalent bonds. This study clarifies the chemical environment provided by MIMs to interact with ions and highlights these molecules as relevant structures to realize ionic sensing.
Collapse
|
18
|
From 8- to 18-Cluster Electrons Superatoms: Evaluation via DFT Calculations of the Ligand-Protected W@Au 12(dppm) 6 Cluster Displaying Distinctive Electronic and Optical Properties. Inorg Chem 2023; 62:3047-3055. [PMID: 36734972 DOI: 10.1021/acs.inorgchem.2c03771] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The iconic W@Au12 icosahedral bare cluster reaches the favorable closed-shell superatomic electron configuration 1S2 1P6 1D10, making it an 18-cluster electron (18-ce) superatom. Here, we pursue the evaluation of a ligand-protected counterpart based on the construction of a fully phosphine-protected [W@Au12(dppm)6] cluster strongly related to the characterized [Au13(dppm)6]5+ homometallic counterpart. The later cluster has the same total number of valence electrons as the former but is considered an 8-ce superatom with 1S2 1P6 configuration. The fundamental differences between 8- and 18-ce species are investigated. The character of the frontier orbitals varies from 1P/1D in the 8-ce case to a 1D/ligand for 18-ce species, enabling an efficient charge transfer toward the ligands upon irradiation, being interesting for electron injection in optoelectronic devices and black absorbers applications. Excited-state properties are also revisited, showing different geometrical and electronic structure variations between 8- and 18-ce species. Moreover, the continuum between the 8- and 18-ce limits has been explored by varying the nature of the encapsulated dopant between group 6 and group 11. The transition between the 8- and 18-ce counts can be formally situated between Pt (8-ce) and Ir (18-ce). Thus, 18-ce derivatives obtained as doped counterparts of homometallic gold clusters can introduce useful alternatives to achieve different properties in related structural motifs, which can be further explored owing to their extension of the well-established versatility of current gold nanoclusters.
Collapse
|
19
|
Correction: Structure effects of Pt 15 clusters for the oxygen reduction reaction: first-principles calculations. Phys Chem Chem Phys 2023; 25:5885. [PMID: 36723247 DOI: 10.1039/d3cp90040a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Correction for 'Structure effects of Pt15 clusters for the oxygen reduction reaction: first-principles calculations' by Peter L. Rodríguez-Kessler et al., Phys. Chem. Chem. Phys., 2023, https://doi.org/10.1039/d2cp05188e.
Collapse
|
20
|
Switch from local to global aromatic character in Möbius carbon nanobelts upon dioxidation. Evaluation of magnetic behavior in neutral and charged species. Phys Chem Chem Phys 2023; 25:4467-4471. [PMID: 36722854 DOI: 10.1039/d2cp05326h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Here we show that recent Möbius carbon nanobelts (MCNBs) can be switched from a local to a global aromatic behavior upon dioxidation. Hence, large aromatic structures can be achieved by the choice of the charge states, giving rise to shielding cone characteristics extended within the overall structure at the nanoscale regime, pushing the limit of aromatic circuits to 198 π-electrons.
Collapse
|
21
|
Structure effects of Pt 15 clusters for the oxygen reduction reaction: first-principles calculations. Phys Chem Chem Phys 2023; 25:4764-4772. [PMID: 36692089 DOI: 10.1039/d2cp05188e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
In the present work, the lowest energy structures and electronic properties of Pt15 clusters are investigated using molecular dynamics simulations. The results showed that the most stable configuration is a capped pyramidal structure, which is 0.8 kal mol-1 lower in energy than a layered structure previously reported [V. Kumar and Y. Kawazoe, Evolution of Atomic and Electronic Structure of Pt Clusters: Planar, Layered, Pyramidal, Cage, Cubic, and Octahedral Growth, Phys. Rev. B: Condens. Matter Mater. Phys., 2008, 77, 205418.]. The result is further confirmed by using both the PW91/cc-pVDZ-PP and PBE/PW approaches including the other representative isomers for Pt15. Due to the interesting structure arrangements found, we have investigated the catalytic activities for the oxygen reduction reaction. We found that the most stable Pt15 clusters are plausible catalyts for the ORR according to their interaction with oxygen species, which is consistent with experiments of Pt clusters with atomicity below 20. The results of the structure, electronic, adsorption and vibrational properties of the clusters are provided.
Collapse
|
22
|
Copper(I), Silver(I), and Gold(I) Ethylene Complexes of Fluorinated and Boron-Methylated Bis- and Tris(pyridyl)borate Chelators. Inorg Chem 2023; 62:1636-1648. [PMID: 36657123 DOI: 10.1021/acs.inorgchem.2c04009] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Bis- and tris-pyridyl borate ligands containing pyridyl donor arms, a methylated boron cap, and a fluorine-lined coordination pocket have been prepared and utilized in coinage metal chemistry. The tris(pyridyl)borate ligand has been synthesized using a convenient boron source, [NBu4][MeBF3]. These N-based ligands permitted the isolation of group 11 metal-ethylene complexes [MeB(6-(CF3)Py)3]M(C2H4) and [Me2B(6-(CF3)Py)2]M(C2H4) (M = Cu, Ag, Au). The gold complexes display the largest coordination-induced upfield shifts of the ethylene 13C resonance relative to that of the free ethylene in their NMR spectra, while the silver complexes show the smallest shift. Solid-state structures of five of these metal-ethylene complexes as well as the related free ligands were established by X-ray crystallography. Surprisingly, all three [MeB(6-(CF3)Py)3]M(C2H4) adopt the rare κ2 coordination mode rather than the typical κ3 coordination mode of facial capping tridentate ligands. Computational analyses indicate that κ2 coordination mode is favored over the κ3-mode in these coinage metal-ethylene complexes and point to the effects CF3-substituents have on κ2/κ3-energy difference. The M-C and M-N bond distances of [MeB(6-(CF3)Py)3]M(C2H4) follow the trend expected based on covalent radii of M(I) ions. The calculated ethylene-M interaction energy of κ2-[MeB(6-(CF3)Py)3]M(C2H4) indicated that the gold(I) forms the strongest interaction with ethylene. A comparison to the related poly(pyrazolyl)borates is also presented.
Collapse
|
23
|
Anion Recognition using Enhanced Halogen Bonding through Intramolecular Hydrogen Bonds – A Computational Insight. NEW J CHEM 2023. [DOI: 10.1039/d2nj05969j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Anions are associated with several biological processes in nature and act as catalysts in the chemicals and fuels production. Non–covalent interactions are useful tools for driving molecular processes. Recently, compounds...
Collapse
|
24
|
Nature and Role of Formal Charge of the ion Inclusion in Hexanuclear Platinium(II) Host-Guest Species. Insights from Relativistic DFT Calculations. Inorganica Chim Acta 2022. [DOI: 10.1016/j.ica.2022.121298] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
|
25
|
Ligand-dictated cluster core characteristics in Au8Se2 gold selenido. Insights from relativistic DFT. Inorganica Chim Acta 2022. [DOI: 10.1016/j.ica.2022.121149] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
|
26
|
Bonding and 13 C-NMR properties of coinage metal tris(ethylene) and tris(norbornene) complexes: Evaluation of the role of relativistic effects from DFT calculations. J Comput Chem 2022; 43:1848-1855. [PMID: 36073752 DOI: 10.1002/jcc.26987] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Revised: 07/28/2022] [Accepted: 08/02/2022] [Indexed: 11/10/2022]
Abstract
The π-complexes of cationic coinage metal ions (Cu(I), Ag(I), Au(I)) provide useful experimental support for understanding fundamental characteristics of bonding and 13 C-NMR patterns of the group 11 triad. Here, we account for the role of relativistic effects on olefin-coinage metal ion interaction for cationic, homoleptic tris-ethylene, and tris-norbornene complexes, [M(η2 -C2 H4 )3 ]+ and [M(η2 -C7 H10 )3 ]+ (M = Cu, Ag, Au), as representative case of studies. The M-(CC) bond strength in the cationic, tris-ethylene complexes is affected sizably for Au and to a lesser extent for Ag and Cu (48.6%, 16.7%, and 4.3%, respectively), owing to the influence on the different stabilizing terms accounting for the interaction energy in the formation of coinage metal cation-π complexes. The bonding elements provided by olefin → M σ-donation and olefin ← M π-backbonding are consequently affected, leading to a lesser covalent interaction going down in the triad if the relativistic effects are ignored. Analysis of the 13 C-NMR tensors provides further understanding of the observed experimental values, where the degree of backbonding charge donation to π2 *-olefin orbital is the main influence on the observed high-field shifts in comparison to the free olefin. This donation is larger for ethylene complexes and lower for norbornene counterparts. However, the bonding energy in the later complexes is slightly stabilized given by the enhancement in the electrostatic character of the interaction. Thus, the theoretical evaluation of metal-alkene bonds, and other metal-bonding situations, benefits from the incorporation of relativistic effects even in lighter counterparts, which have an increasing role going down in the group.
Collapse
|
27
|
Ligand-Induced Cuboctahedral versus Icosahedral Core Isomerism within Eight-Electron Heterocyclic-Carbene-Protected Gold Nanoclusters. Inorg Chem 2022; 61:8623-8628. [PMID: 35640274 DOI: 10.1021/acs.inorgchem.2c01022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The controlled structural modification of ligand-protected gold clusters is evaluated by a proper variation of the size and shape of N-heterocyclic carbene (NHC) ligands. Density functional theory calculations show that the Au13 core of [Au13(NHC)8Br4]+ can be shaped into an icosahedron and/or a so far unexpected cuboctahedron depending on the sterical effect inferred by the NHC ligand side arms. As a result, the cluster properties can be modified, encouraging further exploration on controlled core isomerization in ligated gold cluster chemistry.
Collapse
|
28
|
Abstract
Orbital contributions to the magnetic response depend on the method used to compute them. Here, we show that dissecting nuclear magnetic shielding tensors using natural localized molecular orbitals (NLMOs) leads to anomalous core contributions. The arbitrariness of the assignment might significantly affect the interpretation of the magnetic response of nonplanar molecules such as C60 or [14]helicene and the assessment of their aromatic character. We solve this problem by computing the core- and σ-components of the induced magnetic field (and NICS) and the magnetically induced current density by removing the valence electrons (RVE). We estimate the core contributions to the magnetic response by performing calculations on the corresponding highly charged molecules, such as C6H630+ for benzene, using gauge-including atomic orbitals and canonical molecular orbitals (CMOs). The orbital contributions to nuclear magnetic shielding tensors are usually estimated by employing a natural chemical shielding (NCS) analysis in NLMO or CMO bases. The RVE approach shows that the core contribution to the magnetic response is small and localized at the nuclei, contrary to what NCS calculations suggest. This may lead to a completely incorrect interpretation of the magnetic σ-orbital response of nonplanar structures, which may play a major role in the overall magnetic shielding of the system. The RVE approach is thus a simple and inexpensive way to determine the magnetic response of the core- and σ-electrons.
Collapse
|
29
|
Symmetry collapse due to the presence of multiple local aromaticity in Ge 244. Nat Commun 2022; 13:2149. [PMID: 35444180 PMCID: PMC9021308 DOI: 10.1038/s41467-022-29626-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2021] [Accepted: 03/15/2022] [Indexed: 11/09/2022] Open
Abstract
Understanding the structural changes taking place during the assembly of single atoms leading to the formation of atomic clusters and bulk materials remains challenging. The isolation and theoretical characterization of medium-sized clusters can shed light on the processes that occur during the transition to a solid-state structure. In this work, we synthesize and isolate a continuous 24-atom cluster Ge244−, which is characterized by X-ray diffraction analysis and Energy-dispersive X-ray spectroscopy, showing an elongated structural characteristic. Theoretical analysis reveals that electron delocalization plays a vital role in the formation and stabilization of the prolate cluster. In contrast with carbon atoms, 4 s orbitals of Ge-atoms do not easily hybridize with 4p orbitals and s-type lone-pairs can be localized with high occupancy. Thus, there are not enough electrons to form a stable symmetrical fullerene-like structure such as C24 fullerene. Three aromatic units with two [Ge9] and one [Ge6] species, connected by classical 2c-2e Ge-Ge σ-bonds, are aligned together forming three independent shielding cones and eventually causing a collapse of the global symmetry of the Ge244− cluster. Gaining insight on the structural transformations from atomic clusters to bulk materials is challenging. Here the authors synthesize a continuous cluster of germanium Ge244−, which can be viewed as two terminal Ge9 units bridged via a Ge6 central fragment, and characterize it by several techniques including X-ray diffraction; theoretical analysis indicates the presence of three aligned independent aromatic fragments.
Collapse
|
30
|
Structural and electronic properties for Be-doped Pt n ( n = 1-12) clusters obtained by DFT calculations. Phys Chem Chem Phys 2022; 24:7856-7861. [PMID: 35302144 DOI: 10.1039/d1cp05410d] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
In this work, we have performed a computational study on the structure and electronic properties for Be-doped Ptn (n = 1-12) clusters in the framework of density functional theory (DFT). The most stable structures of the clusters are obtained by a structure search procedure based in simulated annealing. The results show that the PtnBe clusters adopt compact structure motifs with Be situated at the edge sites while only in Pt11Be the Be atom occupies the center site. The energetic parameters showed that Pt5Be, Pt7Be and Pt10Be are the most stable ones. The PtnBe clusters with (n = 5-7) have similar vertical ionization potential (vIP) and vertical electron affinity (vEA) parameters compared to the unary Pt clusters, while Pt9Be and Pt11Be have the higher vEA values. In particular, the d-band center is slightly higher for the doped clusters, suggesting an enhanced reactivity. The σ-holes are found more remarkable for the doped clusters, which are situated in the Be dopant and low coordinated Pt sites. The data on the infrared spectra of the clusters is also provided and showed a significant blue shift due to the vibrational modes of the Be atom. These results are useful for understanding the fundamental properties of Be-doped Ptn clusters in the subnanometer region.
Collapse
|
31
|
N-Heterocyclic carbene derivatives to modify gold superatom characteristics. Tailorable electronic and optical properties of [Au 11(PPh 3) 7LCl 2] + as a cluster from relativistic DFT. Phys Chem Chem Phys 2022; 24:5965-5973. [PMID: 35195620 DOI: 10.1039/d1cp04310b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Atomically precise gold superatoms are useful building blocks whose properties can be tuned by the proper choice of ligands in the protecting ligand layer. Herein, different N-heterocyclic carbene (NHC) derivatives of the prototypical [Au11(PPh3)8Cl2]+ cluster were evaluated by the replacement of a single ligand, which led to isoelectronic [Au11(PPh3)7(NHC)Cl2]+ species, enabling further understanding of the possible changes in the resulting cluster properties. Our results reveal the great variation in the HOMO-LUMO gap and optical features when going from strong to weak σ-donor NHC ligands. The Au11 core retains similar features throughout the series, and the lowest unoccupied orbital (LUMO) is further stabilized, indicating greater π*-NHC character for the weaker σ-donor ligands, which favors directional core-ligand optical charge transfer to a single ligand. The ligand-tailored behavior of the [Au11(PPh3)7LCl2]+ cluster underlies its tunable characteristics, indicating its potential use in novel devices as building blocks of nanostructured materials, which favors further versatility and applications of superatomic clusters.
Collapse
|
32
|
Insight Into the Stability and Electronic and Optical Properties of N-Heterocyclic Carbene Analogues of Halogen/Phosphine-Protected Au 13 Superatomic Clusters. J Phys Chem A 2022; 126:536-545. [PMID: 35044183 DOI: 10.1021/acs.jpca.1c09084] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Atomically precise gold nanoclusters (AuNCs) belong to a relevant area offering useful templates with tunable properties toward functional nanostructures. In this work, we explored the feasible incorporation of N-heterocyclic carbenes (NHCs), as part of the protecting-ligand shell in AuNCs. Our results, which are based on the substitution of phosphine ligands in experimentally characterized AuNCs by NHCs in various eight-electron superatoms Au13 and M4Au9 (M = Cu, Ag), indicate similar electronic structure and stability but somewhat different optical properties. These findings support the feasible obtention of novel targets for explorative synthetic efforts featuring NHC ligands on medium-sized species based on the recurrent Au13 icosahedral core. The hypothetical species appear to be interesting templates for building blocks in nanostructured materials with tuned properties, which encourage experimental exploration of ligand versatility in homo- and heterometallic superatomic clusters.
Collapse
|
33
|
Abstract
A useful ligand involving three pyridyl donor arms and fluorocarbon substituents surrounding the coordination pocket has been assembled and utilized in coinage metal chemistry. This tris(pyridyl)borate serves as an excellent ligand support for the stabilization of ethylene complexes of copper, silver and gold.
Collapse
|
34
|
Ligand-Core Interaction in Ligand-Protected Ag25(XR)18 (X= S, Se, Te) Superatoms. Evaluation of Anchor Atom Role via Relativistic DFT Calculations. Phys Chem Chem Phys 2022; 24:17233-17241. [DOI: 10.1039/d2cp01058e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The isostructural and isoelectronic silver [Ag25(SR)18]- (R=Ligand) cluster to [Au25(SR)18]- gold clusters allows to further understand the fundamental similarities between Au and Ag, at the ultrasmall nanoscale (< 2 nm)...
Collapse
|
35
|
Enabling dual aromaticity in fused nanobelts: evaluation of the magnetic behavior of fused [10]CPP units. Phys Chem Chem Phys 2022; 24:26701-26707. [DOI: 10.1039/d2cp03667c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Cyclo-para-phenylene (CPP) nanobelt structures with curved π-surfaces are of relevance in the development of desirable building units for materials science.
Collapse
|
36
|
On the ligand role in determining the compact or extended metallic core architecture in gold superatoms. Evaluation of electronic and optical properties from relativistic DFT for [Au11(dppp)5]3+ and [Au11(dppe)6]3+ clusters. Polyhedron 2022. [DOI: 10.1016/j.poly.2021.115572] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
|
37
|
Nature of hydride and halide encapsulation in Ag 8 cages: insights from the structure and interaction energy of [Ag 8(X){S 2P(O iPr) 2} 6] + (X = H -, F -, Cl -, Br -, I -) from relativistic DFT calculations. Phys Chem Chem Phys 2021; 24:452-458. [PMID: 34897316 DOI: 10.1039/d1cp04249a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Unraveling the different contributing terms to an efficient anion encapsulation is a relevant issue for further understanding of the underlying factors governing the formation of endohedral species. Herein, we explore the favorable encapsulation of hydride and halide anions in the [Ag8(X){S2P(OPr)2}6]+ (X- = H, 1, F, 2, Cl, 3, Br, 4, and, I, 5) series on the basis of relativistic DFT-D level of theory. The resulting Ag8-X interaction is sizable, which decreases along the series: -232.2 (1) > -192.1 (2) > -165.5 (3) > -158.0 (4) > -144.2 kcal mol-1 (5), denoting a more favorable inclusion of hydride and fluoride anions within the silver cage. Such interaction is mainly stabilized by the high contribution from electrostatic type interactions (80.9 av%), with a lesser contribution from charge-transfer (17.4 av%) and London type interactions (1.7 av%). Moreover, the ionic character of the electrostatic contributions decreases from 90.7% for hydride to 68.6% for the iodide counterpart, in line with the decrease in hardness according to the Pearson's acid-base concept (HSAB) owing to the major role of higher electrostatic interaction terms related to the softer (Lewis) bases. Lastly, the [Ag8{S2P(OPr)2}6]2+ cluster is able to adapt its geometry in order to maximize the interaction towards respective monoatomic anion, exhibiting structural flexibility. Such insights shed light on the physical reasoning necessary for a better understanding of the different stabilizing and destabilizing contributions related to metal-based cavities towards favorable incorporation of different monoatomic anions.
Collapse
|
38
|
Terminal and Internal Alkyne Complexes and Azide-Alkyne Cycloaddition Chemistry of Copper(I) Supported by a Fluorinated Bis(pyrazolyl)borate. MOLECULES (BASEL, SWITZERLAND) 2021; 27:molecules27010016. [PMID: 35011246 PMCID: PMC8746352 DOI: 10.3390/molecules27010016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Revised: 12/17/2021] [Accepted: 12/18/2021] [Indexed: 12/19/2022]
Abstract
Copper plays an important role in alkyne coordination chemistry and transformations. This report describes the isolation and full characterization of a thermally stable, copper(I) acetylene complex using a highly fluorinated bis(pyrazolyl)borate ligand support. Details of the related copper(I) complex of HC≡CSiMe3 are also reported. They are three-coordinate copper complexes featuring η2-bound alkynes. Raman data show significant red-shifts in C≡C stretch of [H2B(3,5-(CF3)2Pz)2]Cu(HC≡CH) and [H2B(3,5-(CF3)2Pz)2]Cu(HC≡CSiMe3) relative to those of the corresponding alkynes. Computational analysis using DFT indicates that the Cu(I) alkyne interaction in these molecules is primarily of the electrostatic character. The π-backbonding is the larger component of the orbital contribution to the interaction. The dinuclear complexes such as Cu2(μ-[3,5-(CF3)2Pz])2(HC≡CH)2 display similar Cu-alkyne bonding features. The mononuclear [H2B(3,5-(CF3)2Pz)2]Cu(NCMe) complex catalyzes [3 + 2] cycloadditions between tolyl azide and a variety of alkynes including acetylene. It is comparatively less effective than the related trinuclear copper catalyst {μ-[3,5-(CF3)2Pz]Cu}3 involving bridging pyrazolates.
Collapse
|
39
|
Occurrence of Double Bond in π-Aromatic Rings: An Easy Way to Design Doubly Aromatic Carbon-Metal Structures. Molecules 2021; 26:molecules26237232. [PMID: 34885812 PMCID: PMC8659221 DOI: 10.3390/molecules26237232] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2021] [Revised: 11/24/2021] [Accepted: 11/26/2021] [Indexed: 11/16/2022] Open
Abstract
A chemical bonding of several metallabenzenes and metallabenzynes was studied via an adaptive natural density partitioning (AdNDP) algorithm and the induced magnetic field analysis. A unique chemical bonding pattern was discovered where the M=C (M: Os, Re) double bond coexists with the delocalized 6c-2e π-bonding elements responsible for aromatic properties of the investigated complexes. In opposition to the previous description where 8 delocalized π-electrons were reported in metallabenzenes and metallabenzynes, we showed that only six delocalized π-electrons are present in those molecules. Thus, there is no deviation from Hückel's aromaticity rule for metallabenzynes/metallabenzenes complexes. Based on the discovered bonding pattern, we propose two thermodynamically stable novel molecules that possess not only π-delocalization but also retain six σ-delocalized electrons, rendering them as doubly aromatic species. As a result, our investigation gives a new direction for the search for carbon-metal doubly aromatic molecules.
Collapse
|
40
|
When SF 5 outplays CF 3: effects of pentafluorosulfanyl decorated scorpionates on copper. Chem Sci 2021; 12:14618-14623. [PMID: 34881014 PMCID: PMC8580053 DOI: 10.1039/d1sc04846e] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Accepted: 10/15/2021] [Indexed: 01/01/2023] Open
Abstract
Polyfluorinated, electron-withdrawing, and sterically demanding supporting ligands are of significant value in chemistry. Here we report the assembly and use of a bis(pyrazolyl)borate, [Ph2B(3-(SF5)Pz)2]- that combines all such features, and involves underutilized pentafluorosulfanyl substituents. The ethylene and carbonyl chemistry of copper(i) supported by [Ph2B(3-(SF5)Pz)2]-, a comparison to the trifluoromethylated counterparts involving [Ph2B(3-(CF3)Pz)2]-, as well as copper catalyzed cyclopropanation of styrene with ethyl diazoacetate and CF3CHN2 are presented. The results from cyclopropanation show that SF5 groups dramatically improved the yields and stereoselectivity compared to the CF3.
Collapse
|
41
|
Catalytic effect of [trans-Cu(μ-OH)(μ-dmpz)]6 on the thermal decomposition of ammonium perchlorate. Polyhedron 2021. [DOI: 10.1016/j.poly.2021.115464] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
|
42
|
Contrasting Bonding Extremes in Two [Ge 6] n- Complexes: A Wadian Polyhedron ( n = 2) versus a Hydrocarbon-like 2c-2e Polygermanide ( n = 12). Inorg Chem 2021; 60:14697-14705. [PMID: 34555280 DOI: 10.1021/acs.inorgchem.1c01799] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
[Nb(η6-C6H3Me3)2] reacts with ethylenediamine (en) solutions of K4Ge9 in the presence of 18-crown-6 to give [(η6-C6H3Me3)NbHGe6]2- (1) and [(η6-C6H3Me3)NbGe6Nb(η6-C6H3Me3)]2- (2) as their corresponding [K(18-crown-6)]+ salts. The crystalline solids are dark brown, air-sensitive, and sparingly soluble or insoluble in most solvents. The [K(18-crown-6)]+ salts of cluster ions 1 and 2 have been characterized by energy-dispersive X-ray (EDX) analysis, NMR studies, single-crystal X-ray diffraction, and electrospray ionization time-of-flight (ESI-TOF) mass spectrometry studies. Cluster ions 1 and 2 have markedly different [Ge6] moieties: an electron-deficient carborane-like subunit in 1 and a two-center, two-electron cyclohexane-like subunit in 2.
Collapse
|
43
|
Corrigendum: [Sn 8 ] 6- -Bridged Mixed-Valence Zn I /Zn II in {[K 2 ZnSn 8 (ZnMes)] 2 } 4- Inverse Sandwich-Type Cluster Supported by a Zn I -Zn I Bond. Angew Chem Int Ed Engl 2021; 60:18916. [PMID: 34402575 DOI: 10.1002/anie.202108772] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
44
|
Evaluation of ultrasmall coinage metal M 13(dppe) 6 M = Cu, Ag, and Au clusters. Bonding, structural and optical properties from relativistic DFT calculations. Phys Chem Chem Phys 2021; 23:18035-18043. [PMID: 34386809 DOI: 10.1039/d1cp02451e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Ultrasmall ligand-protected clusters are prototypical species for evaluating the variation at the bottom of the nanoscale range. Here we explored the ultrasmall gold-phosphine M13(dppe)6 cluster, as a prototypical framework to gain insights into the fundamental similarities and differences between Au, Ag, and Cu, in the 1-3 nm size range, via relativistic DFT calculations. Different charge states involving 8- and 10-cluster electron (ce) species with a 1S21P6 and 1S21P61D2 configuration, leading to structural modification in the Au species between Au13(dppm)65+ and Au13(dppm)63+, respectively. Furthermore, this structural distortion of the M13 core is found to occur to a lower degree for the calculated Ag and Cu counterparts. Interestingly, optical properties exhibit similar main patterns along with the series, inducing a blue-shift for silver and copper, in comparison to the gold parent cluster. For 10-ce species, the main features of 8-ce are retained with the appearance of several weak transitions in the range. The ligand-core interaction is enhanced for gold counterparts and decreased for lighter counterparts resulting in the Au > Cu > Ag trend for the interaction stabilization. Hence, the Ag and Cu counterparts of the Au13(dppm)6 cluster appear as useful alternatives, which can be further explored towards different cluster alternatives for building blocks for nanostructured materials.
Collapse
|
45
|
Ternary aromatic and anti-aromatic clusters derived from the hypho species [Sn 2Sb 5] 3. Nat Commun 2021; 12:4465. [PMID: 34294702 PMCID: PMC8298489 DOI: 10.1038/s41467-021-24706-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2021] [Accepted: 07/01/2021] [Indexed: 02/06/2023] Open
Abstract
Heterometallic clusters have attracted broad interests in the synthetic chemistry due to their various coordination modes and potential applications in heterogeneous catalysis. Here we report the synthesis, experimental, and theoretical characterizations of four ternary clusters ([M2(CO)6Sn2Sb5]3- (M = Cr, Mo), and [(MSn2Sb5)2]4-, (M = Cu, Ag)) in the process of capturing the hypho- [Sn2Sb5]3- in ethylenediamine (en) solution. We show that the coordination of the binary anion to transition-metal ions or fragments provides additional stabilization due to the formation of locally σ-aromatic units, producing a spherical aromatic shielding region in the cages. While in the case of [Mo2(CO)6Sn2Sb5]3- stabilization arises from locally σ-aromatic three-centre and five-centre two-electron bonds, aromatic islands in [(AgSn2Sb5)2]4- and [(CuSn2Sb5)2]4- render them globally antiaromatic. This work describes the coordination chemistry of the versatile building block [Sn2Sb5]3-, thus providing conceptual advances in the field of metal-metal bonding in clusters.
Collapse
|
46
|
Reply to 'Comment on "Structural characterization, reactivity, and vibrational properties of silver clusters: A new global minimum for Ag 16"' by P. V. Nhat, N. T. Si, L. V. Duong and M. T. Nguyen, Phys. Chem. Chem. Phys., 2021, 23, DOI: D1CP00646K. Phys Chem Chem Phys 2021; 23:12904-12906. [PMID: 34042926 DOI: 10.1039/d1cp01481a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Recently, P. V. Nhat et al., have discussed and commented on our article (DOI: 10.1039/D0CP04018E) for the case of the most stable structure of Ag15. They have found a new most stable structure (labeled as 15-1) in comparison to the putative global minimum reported by us, which is a four layered 1-4-6-4 stacking structure with a C2v point group (15-2). In this reply, we have performed a larger structure search which allowed us to confirm the results of Nhat et al. The results show the existence of multiple isoenergetic isomers with similar structure motifs for the Ag15 system, increasing the problem complexity to locate the global minimum. The results in regard to the structure and electronic properties of the new lowest energy structure are discussed.
Collapse
|
47
|
Aromaticity in Phenyl Decorated closo-Monocarboranes. Planar-Spherical Aggregates Involving 7-12-Vertex Cages. J Phys Chem A 2021; 125:4861-4866. [PMID: 34048262 DOI: 10.1021/acs.jpca.1c02934] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The characterized phenyl decorated closo-monocarboranes with variable sizes from 7- to 12-vertex cages, [Ph-closo-CBnHn]-, n = 6-11, allow us to address the role of the varying size and shape of the carborane cage in dual planar-spherical aromatic species. Our results show the formation of adjacent shielding cone characteristics enabled from both planar and spherical aromatic fragments, despite the different structures of the closo-monocarboranes. Under a field perpendicular to the phenyl ring, both shielding cones are enabled, which overlap at long-range regions, in contrast to other orientations leading to a short-range response from the planar aromatic fragment. Thus, a two- or one-aromatic circuit is enabled selectively within the same molecular unit, by controlling the orientation of the external field. Along with the series, a variable extension of the shielding cone from the carborane cage is observed, which is larger for the -CB11H11 case, decreasing toward -CB6H6, denoting a similar extension from both the planar and spherical aromatic regions at the [4-Ph-closo-4-CB8H8]- (4) counterpart. The analysis of such multiple aromatic structures shows that, despite the different sizes and shapes of the closo cages, a similar aromatic behavior remains. In addition, the anisotropy of the induced magnetic field is given graphically, denoting a larger anisotropy for the planar aromatic moiety owing to its two-dimensional structure, which is suggested to discriminate between planar and spherical aromatic fragments within the same molecule.
Collapse
|
48
|
On Heteronuclear Isoelectronic Alternatives to [Au13(dppe)5Cl2]3+: Electronic and Optical Properties of the 18-Electron Os@[Au12(dppe)5Cl2] Cluster from Relativistic Density Functional Theory Computations. Inorg Chem 2021; 60:8173-8180. [DOI: 10.1021/acs.inorgchem.1c00799] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
|
49
|
[Sn 8 ] 6- -Bridged Mixed-Valence Zn I /Zn II in {[K 2 ZnSn 8 (ZnMes)] 2 } 4- Inverse Sandwich-Type Cluster Supported by a Zn I -Zn I Bond. Angew Chem Int Ed Engl 2021; 60:9990-9995. [PMID: 33682237 DOI: 10.1002/anie.202102578] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2021] [Indexed: 11/08/2022]
Abstract
Since [Sn8 ]6- was discovered from the solid-state phase in 2000, its solution chemistry has been elusive due to the high charges and chemical activity. Herein, we report the synthesis and characterization of an inverse sandwich-type cluster dimer {[K2 ZnSn8 (ZnMes)]2 }4- (1 a), in which the highly charged [Sn8 ]6- is captured by mixed-valence ZnI /ZnII to form the dimer {closo-[Zn2 Sn8 ]}2 moieties bridged by a Zn-Zn bond. Such Zn-Sn cluster not only exhibits a novel example of mixed-valence ZnI /ZnII for stabilizing highly active anion species, but also indicates the [Sn8 ]6- cluster can act as a novel bridging ligand, like arene, with a η4 :η4 -fashion. Theoretical calculations indicate that a significant delocalization of electrons over Zn atoms plays a vital role in the stabilization of the [Sn8 ]6- species. The AdNDP and magnetic response analyses clearly showed the presence of local σ-aromaticity in three cluster fragments: two ZnSn4 caps and Sn8 square antiprism.
Collapse
|
50
|
Aromaticity of ortho and meta 8-Cycloparaphenylene and Their Dications: Induced Magnetic Field Analysis with Localized and Delocalized Orbitals in Strained Nanohoops. Chemphyschem 2021; 22:741-751. [PMID: 33620136 DOI: 10.1002/cphc.202100057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 02/21/2021] [Indexed: 11/06/2022]
Abstract
Dications of cycloparaphenyles ([n]CPPs) are known to exhibit in-plane global aromaticity, contained in a nanobelt structure. Recently synthesized ortho and meta isomers of [n]CPPs break the radial symmetry of π structure incorporating perpendicular oriented π orbitals. Herein we set to explore the aromaticity of neutral and dicationic ortho and meta isomers of [8]CPP by dissecting the induced magnetic field to contributions of the twofold radial/perpendicular π system using delocalized canonical molecular orbitals (CMO), and introducing the natural localized molecular orbitals (NLMO) analysis with DFT methods. The dications sustain a reduced global aromatic character of the radial π system under a perpendicular orientation of the external field which declines from ortho to meta isomer and reinforces local aromaticity of ortho ring while it destroys aromaticity of meta ring. Aromaticity variations are determined by symmetry governed rotational excitations of frontier π orbitals. The parallel orientation reveals a substantial reduction of local aromaticity verified with NICSπ analysis and electron delocalization indices.
Collapse
|